Blood is conventionally processed, e.g., separated into components, to provide a variety of valuable products such as transfusion products. Blood components or products such as buffy coat and platelets may be pooled during processing, e.g., 4–6 units of platelet concentrate can be pooled before administration as a transfusion product. Additionally, blood components processed in a closed system (e.g., without exposing the components to the outside environment) can be stored before administration. For example, red blood cells can be stored for several weeks, and platelets can be stored for several days (e.g., 5 days according to current U.S. practice).
Stored and/or non-stored components can include undesirable material such as bacteria. Bacteria can contaminate the blood or blood component during blood collection (including blood sampling) and/or storage. Other sources of contamination include the donor's blood, the environment (including the air, and the equipment in the environment), the donor's skin plug, and the phlebotomist.
Since some blood components (particularly platelets) are typically stored at ambient temperatures (e.g., about 22–26° C.), the problem of contamination may be magnified, as most bacteria reproduce more rapidly at ambient temperatures than at, for example, about 2–8° C.
Contaminated blood products, especially bacterially contaminated blood products, pose a potential health risk to those who come into contact with, or receive, these products. For example, the administration of transfusion products with bacterial contamination can have adverse affects on the recipient, and the administration of platelets with massive levels of bacterial contamination is implicated in about 150 cases of severe morbidity or death each year in the U.S.
Typical bacterial detection techniques include optical measures of turbidity or color changes correlated with growth of the bacteria. Bacterial detection techniques are generally labor- and time-intensive and may require expensive equipment. Some of the techniques may provide inaccurate results and/or may introduce contamination from the environment into the samples.
The present invention provides for ameliorating at least some of the disadvantages of the prior art. These and other advantages of the present invention will be apparent from the description as set forth below.